Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already indicate readOnlyHint and openWorldHint, so the description adds value by disclosing ordering ('newest first'), visibility ('including unlisted ones'), and default scope behavior when an API key is configured. This goes beyond the annotations and gives useful behavioral context without contradiction.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is three sentences, front-loaded with the core purpose, then expands on scope behavior, and ends with an alternative pointer. Every sentence adds distinct value with no redundancy or filler.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

With a simple 2-parameter schema, clear annotations, no output schema needed, and sibling differentiation included, the description provides complete guidance. It covers parameters, defaults, ordering, and alternatives without requiring additional explanation.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The input schema provides full descriptions for both parameters (100% coverage). The description adds semantic meaning by explaining the default scope ('mine' when key is set) and the behavior of 'public' as the public feed, which enriches the parameter documentation beyond the schema.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states the tool's function: 'List recent Pastepile pastes.' It specifies a verb ('List') and a resource ('Pastepile pastes'), and distinguishes itself from siblings by noting the default scope behavior and explicitly recommending pastepile_search for targeted lookups.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description explains when to use this tool versus alternatives: 'For targeted lookups use pastepile_search instead.' It also clarifies the scope parameter behavior depending on API key configuration, giving clear context for choosing between 'mine' and 'public'.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.